Portion of a shoe sole



FIG. 1 is a front perspective view of a portion of a shoe sole showing my new design;

FIG. 2 is a side view thereof; and,

FIG. 3 is a rear perspective view thereof.

The uneven broken line immediately adjacent to the shaded area represents an unclaimed boundary of the design. The uneven broken line showing of the remainder of the show is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a shoe sole, as shown and described. 